1. Field of the Invention
The invention herein pertains to window locks and the like and particularly pertains to a security lock for a window sash. The cam of the security lock includes a sweep arm channel having an elongate-shaped outer wall for engaging a keeper.
2. Description of Background Art
In recent years, burglars have become adapt at opening sash type windows from the outside of a house or other building by first removing the window screen and placing a putty knife or similar thin bladed instrument between the sashes to rotate the cam to an unlocked posture. The blade is used by unauthorized persons to urge the rotatable cam to disengage the cam from the keeper. Once the cam has been disengaged, the sash is then openable for entry purposes. Attempts have been made to secure such windows such as by use of extra locks or by drilling holes in the sash and window frame and inserting nails or steel rods therein for immobilization. However, adding locking devices tends to inconvenience the home or business owner and obstructs the intended function of the window. Certain sash window locks have been designed in the past to prevent unauthorized entry such as shown in U.S. Pat. No. 6,142,541. Another sash window lock, such as disclosed in U.S. application Ser. No. 11/136,066, has a tab that is rotatable in a well of a cam, and a cam that is slidable within the housing.
Window reinforcements, locks and other means to prevent entry are often expensive, inconvenient and are often difficult to use and require extra thought, time and effort by the owner. Sometimes these other means to prevent entry are installed, and when not installed, conventional locks provide little if any protection against unauthorized entry.